<?php

if (! defined ( 'BASEPATH' ))
	exit ( 'No direct script access allowed' );
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 4.3.2 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2006 - 2011 EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 2.0
 * @filesource
 */

// ------------------------------------------------------------------------


/**
 * CodeIgniter Memcached Caching Class
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Core
 * @author		ExpressionEngine Dev Team
 * @link
 */

class CI_Cache_memcached extends CI_Driver {
	
	private $_memcached; // Holds the memcached object
	

	protected $_memcache_conf = array ('default' => array ('default_host' => '127.0.0.1', 'default_port' => 11211, 'default_weight' => 1 ) );
	
	// ------------------------------------------------------------------------
	

	/**
	 * Fetch from cache
	 *
	 * @param 	mixed		unique key id
	 * @return 	mixed		data on success/false on failure
	 */
	public function get($id) {
		$data = $this->_memcached->get ( $id );
		
		return (is_array ( $data )) ? $data [0] : FALSE;
	}
	
	// ------------------------------------------------------------------------
	

	/**
	 * Save
	 *
	 * @param 	string		unique identifier
	 * @param 	mixed		data being cached
	 * @param 	int			time to live
	 * @return 	boolean 	true on success, false on failure
	 */
	public function save($id, $data, $ttl = 60) {
		return $this->_memcached->add ( $id, array ($data, time (), $ttl ), $ttl );
	}
	
	// ------------------------------------------------------------------------
	

	/**
	 * Delete from Cache
	 *
	 * @param 	mixed		key to be deleted.
	 * @return 	boolean 	true on success, false on failure
	 */
	public function delete($id) {
		return $this->_memcached->delete ( $id );
	}
	
	// ------------------------------------------------------------------------
	

	/**
	 * Clean the Cache
	 *
	 * @return 	boolean		false on failure/true on success
	 */
	public function clean() {
		return $this->_memcached->flush ();
	}
	
	// ------------------------------------------------------------------------
	

	/**
	 * Cache Info
	 *
	 * @param 	null		type not supported in memcached
	 * @return 	mixed 		array on success, false on failure
	 */
	public function cache_info($type = NULL) {
		return $this->_memcached->getStats ();
	}
	
	// ------------------------------------------------------------------------
	

	/**
	 * Get Cache Metadata
	 *
	 * @param 	mixed		key to get cache metadata on
	 * @return 	mixed		FALSE on failure, array on success.
	 */
	public function get_metadata($id) {
		$stored = $this->_memcached->get ( $id );
		
		if (count ( $stored ) !== 3) {
			return FALSE;
		}
		
		list ( $data, $time, $ttl ) = $stored;
		
		return array ('expire' => $time + $ttl, 'mtime' => $time, 'data' => $data );
	}
	
	// ------------------------------------------------------------------------
	

	/**
	 * Setup memcached.
	 */
	private function _setup_memcached() {
		// Try to load memcached server info from the config file.
		$CI = & get_instance ();
		if ($CI->config->load ( 'memcached', TRUE, TRUE )) {
			if (is_array ( $CI->config->config ['memcached'] )) {
				$this->_memcache_conf = NULL;
				
				foreach ( $CI->config->config ['memcached'] as $name => $conf ) {
					$this->_memcache_conf [$name] = $conf;
				}
			}
		}
		
		$this->_memcached = new Memcached ();
		
		foreach ( $this->_memcache_conf as $name => $cache_server ) {
			if (! array_key_exists ( 'hostname', $cache_server )) {
				$cache_server ['hostname'] = $this->_default_options ['default_host'];
			}
			
			if (! array_key_exists ( 'port', $cache_server )) {
				$cache_server ['port'] = $this->_default_options ['default_port'];
			}
			
			if (! array_key_exists ( 'weight', $cache_server )) {
				$cache_server ['weight'] = $this->_default_options ['default_weight'];
			}
			
			$this->_memcached->addServer ( $cache_server ['hostname'], $cache_server ['port'], $cache_server ['weight'] );
		}
	}
	
	// ------------------------------------------------------------------------
	

	/**
	 * Is supported
	 *
	 * Returns FALSE if memcached is not supported on the system.
	 * If it is, we setup the memcached object & return TRUE
	 */
	public function is_supported() {
		if (! extension_loaded ( 'memcached' )) {
			log_message ( 'error', 'The Memcached Extension must be loaded to use Memcached Cache.' );
			
			return FALSE;
		}
		
		$this->_setup_memcached ();
		return TRUE;
	}

	// ------------------------------------------------------------------------


}
// End Class

/* End of file Cache_memcached.php */
/* Location: ./system/libraries/Cache/drivers/Cache_memcached.php */